Published October 2, 2025
By Taylor Hodge, US Agrochemicals and Fossil Fuels Campaigner, Lisa Tostado, Agrochemicals and Fossil Fuel Campaigner, and Lindsey Jurca Durland, Senior Communications Campaign Specialist at the Center for International Environmental Law
Fossil fuels permeate our food systems — from transportation and energy to plastic packaging. Estimates show that food systems consume roughly 15% of global fossil fuels each year. One major driver of this fossil fuel dependence often flies under the radar: fertilizers. Namely, synthetic nitrogen fertilizers play a role in fueling the climate crisis and harming human health — addressing them is key to building a just, fossil-free food future.
Fertilizers Are Often Fossil Fuels in Another Form
More than half of synthetic fertilizers used worldwide are nitrogen-based and derived from fossil gas or coal. This is why we call them fossil fertilizers.
Plants need nutrients like nitrogen (N), phosphorus (P), and potassium (K) to grow. Virtually all synthetic nitrogen fertilizer is made from fossil fuels — about 70% fossil gas and nearly all the rest from coal. While phosphorus and potassium are produced from mined ores, producing any synthetic fertilizer is energy-intensive, and the mining industry is heavily dependent on fossil fuels. Like other fossil fuel products, fossil fertilizers cause extensive harm to the environment, climate, and human health throughout their entire supply chain.
Extraction: The Hidden Cost
The fossil fertilizer supply relies on the extraction of fossil gas and coal. While all extraction is harmful, techniques like fracking, common in the US, have been linked to leukemia, preterm births, asthma, and early death in older people.
Production: Toxic Factories Are Terrible Neighbors
Fossil fertilizer plants pollute the land, water, and air of surrounding communities, harming ecosystems and human health. In 2021, thirty US nitrogen fertilizer facilities discharged 7.7 million pounds of nitrogen pollution, including 3.9 million pounds of ammonia, the key intermediate product for all synthetic nitrogen fertilizers, into waterways. One of the largest ammonia plants, CF Industries’ Donaldsonville Complex in Louisiana, emits millions of pounds of toxic chemicals each year, including ammonia itself and formaldehyde, a probable carcinogen.
In the US, petrochemical manufacturing — including fertilizer facilities — is among the sectors that impose disproportionate toxic burdens on Black, Brown, Indigenous, and poor communities. Proximity to petrochemical infrastructure can lead to elevated rates of cancer, reproductive health problems, and respiratory illness.
Application
Fossil fertilizer use releases potent greenhouse gases, including nitrous oxide (N2O), which has the potential to warm the planet 273 times more than CO2, and is also the most important stratospheric ozone-depleting emission.
As much as 80% of reactive nitrogen applied as fertilizer doesn’t feed food production but instead pollutes soil, waterways, and the atmosphere. Nutrient pollution can contaminate groundwater, create harmful algal blooms, and cause dead zones in oceans, such as in the Gulf of Mexico, where the dead zone stretches over 4,000 square miles.
The use of synthetic fertilizers may contribute to nitrate contamination in drinking water. Nitrate contamination in drinking water is a well-known risk factor for ‘blue baby’ syndrome or infant methemoglobinemia, which, in severe cases, can cause coma and death. Nitrate ingestion can also form N-nitroso compounds (NOCs), which are probable carcinogens according to the International Agency for Research on Cancer (IARC). While more research should be done, a growing body of evidence has begun to link nitrate ingestion to colorectal cancer, thyroid disease, and neural tube defects.
Fertilizers Chain Food Systems to the Fossil Fuel Industry
Food systems account for roughly 15% of global fossil fuel consumption each year, driving as many emissions as all EU countries and Russia combined. In 2020, 4% of the world’s gas supply was used to make ammonia, the precursor to all synthetic nitrogen fertilizers. About 70% of the ammonia globally is destined for fertilizers, with demand expected to rise.
Corporate ties further link the fossil fuel and fertilizer industries with overlapping board members, as well as several oil and gas companies owning stakes in fertilizer production or with chemical divisions involved in agrochemical production.
Food Systems Must Be Reimagined
According to a report by the Food System Economics Commission, the hidden costs of fossil-dependent food systems tally up to trillions of dollars annually, intensifying “persistent hunger, undernutrition, the obesity epidemic, loss of biodiversity, environmental damage, and climate change.” Recent estimates registered the hidden cost of our fossil-bound, industrial food system at 15 –20 trillion USD per year– roughly equivalent to the 2025 GDP of China or of all EU countries combined
Industrialized agriculture, sparked by the Green Revolution of the 1950s, has tied our food systems to fossil fuels through fertilizers, pesticides and machines, displacing sustainable agricultural approaches like agroecology that maintain ecosystem integrity and nutrition. This was emphasized in 2021, by the UN Special Rapporteur on the right to food.
Solutions are Community-led and Fossil Free
The path forward is clear: We must drastically reduce synthetic fertilizer use and holistically transform our food systems. This means supporting practices that enhance soil’s natural fertility, such as planting legumes, crop rotation, adding compost and manure, and shifting global diets away from fertilizer-intensive foods like meat and dairy. A recent study shows that with such changes, the world can likely feed 10 billion people without synthetic nitrogen fertilizer or farmland expansion.
Agroecology, which combines indigenous knowledge and conventional scientific methods, could offer a blueprint for an agricultural transition with immense economic, social, and environmental benefits, including greater resilience to a changing climate.
The Time to Act Is Now
A food system reliant on fossil fuels is one that fuels climate change, erodes our environment, and harms our health. We need bold shifts toward agroecology and community-led, fossil-free agriculture.
Our ability to feed the future depends on reimagining and rebuilding systems that nourish people — not fossil fuel profits.
See our Frack to Fork fact sheet for more information on Fossil Fertilizers.
Fossil Fertilizer: How It’s Made
Fossil fertilizer production relies on fossil fuels for both feedstock and energy. Hydrogen is separated from the fossil feedstock and mixed with nitrogen (from the air) through the energy-intensive Haber-Bosch process to create ammonia (NH3), the base for all nitrogen fertilizers. This process emits 1.9 tons of carbon dioxide (CO2) for every ton of ammonia. Ammonia may then be converted into ammonium nitrate or urea (CO(NH2)2) — common forms of fertilizers. Many synthetic fertilizers combine fossil-based and mined inputs.
